1. Technical Field
This invention generally relates to an emergency actuation system for overhead doors, and specifically to an emergency door opening actuator that causes an automatic overhead door to open and remain open in case of a fire or associated high temperatures.
2. State of the Art
Fire doors with actuators that cause the doors to close in emergency conditions are known. These fire door systems generally close overhead doors under the influence of gravity. Many such doors have fusible links that melt and break at temperatures above a certain range. These door systems thus have mechanical door closing actuation mechanisms and mechanical closing mechanism. Some fire doors have been developed that have electric powered door closing mechanisms and electronic door closing actuation mechanisms.
Other door systems have been developed for assuring ventilation when a high level of a toxic gas such as carbon monoxide has been detected. Once again, these door systems include electronic sensors and are actuated to open a door when a minimum level of carbon monoxide or other gas is detected.
There is a deficiency of devices for assuring egress from a garage or house through the garage door. Several persons including fire fighters have lost their lives or been severely injured by being trapped in a garage during a fire. These deaths and injuries continue to occur, indicating a need in the art for a simple, inexpensive, yet effective device that will cause an overhead door to open and allows egress in the case of a fire.